Documentation/Networking

Setting up networking in QEMU requires configuring a networking backend and choosing a virtual network card to emulate. This section deals with configuring a networking backend.

Choosing which networking backend to use

Slirp (user networking)

The slirp networking backend implements a full TCP/IP stack within QEMU and uses that stack to implement a virtual NAT'd networked. This is the default networking backend and generally is the easiest to use. It has the following limitations:

• there is a lot of overhead so the performance is poor
• ICMP traffic does not work (you cannot use ping within a guest)
• the guest is not directly accessible from the host or the external network

Tap

The tap networking backend makes use of a tap networking device in the host. It offers very good performance and can be configured to create virtually any type of network topology. Unfortunately, it requires configuration of that network topology in the host which tends to be different depending on the operating system you are using. Generally speaking, it also requires that you invoke QEMU as root.

How do I...

• Use tap to let guests be visible on the host network
• Use tap with a wireless adapter on the host
• Forward ports with slirp